Failure to upgrade firmware

Hi
I have been trying to upgrade the firmware of my wipy. It still runs the original version so thought it would be a good idea.
Downloaded various versions of the firmware from github as directed and used filezilla to move the bin file to the wipy. However after reboot they all fail. I can no longer access the wipy and have to reinstall version 1 to get it to work again. These are the units from the original kickstarter campaign